Fixed .funcptr property of delegates, no longer uses the infamous DMD rewrites to pointer arithmetic, instead a GEPExp has been introduced.

tests/mini/dgfuncptr.d

@@ -0,0 +1,9 @@
+void main()
+{
+  void foo() {}
+
+  auto dg = &foo;
+
+  if(dg.funcptr is null)
+  { assert(0); }
+}